Hydraulic pump or motor



i Dec. 7, 1937. E. K. BENEDEK 2,101,729

` HYDRAU 1 v Filed May 22, 1934 3 Sheets-Sheet l 4 ya' mm1/111Wli9 www 1 ELKREENEDEK 3 Sheets-Sheet 5 E. K. BENEDEK HYDRAULIC PUMP OR MOTOR Flled May 22 1934 Dec. 7, 1937.

Patented Dec. 7, 1937 UNITED STATES PATENT OFFICE I 2,101,729 HYDRAULIC PUMP on MOTOR Elek K. Beneden-Mount Gilead, ohio Application May z2, 1934, serial No. 726,961

7 Claims. This invention relates to pumps and motors `of the radial piston type and has for particular-` object the provision of an improved structure which will be more eiiicient, easier to manufacture and assemble and disassemble, than pumps and motors of this type -heretofore designed, and is a continuation in part of my prior application Ser. No. 716,451, filed March 20, 1934.

One of the main objects of this invention is the provision of means to obtain perfect alignment between the main relatively rotating parts (valve pintlevand rotor) so that after assembly no frictional wear can take place between these parts, and consequently a longer useful life and greater hydraulic efliciency will be obtained.

Further objects of the invention include the provision of'a novel arrangement of piston actuating parts whereby the replacement of pistons and piston crosspins is made feasible very easily by disassembling the piston actuating member, in order to exchange or replace worn or defective inner parts at minimum cost and time.

A further object lies in the application of Vstandard interchangeable bearings for the piston actuating assembly to thereby facilitate easy repair and unrestricted production.

A further object of my invention is the elimination of frictional drag between the piston load carrying members and the piston crosshead connections to thereby eliminate heat, friction, and

wear such as would be likelyto cause loose crosshead connections and knocks in the mechanism.

A further object is the reduction of the number of parts in the piston crosshead connections with the operating reaction members to thereby reduce. the radial dimensions of the mechanism when arranged tobe used as a pump, andalso the size of the crosshead actuating bearings,

permitting increase in the running speed and` alsov increase in the capacity of the pump, with-` out increasing its overall dimensions and size.

A further object of the invention is the reduction of the axial dimensions of the pump, so that (otros-161) ture of anti-friction bearings, which means will be disposed circularly intermediately of the elements and align and mutually support the inner bearing race members to thereby provide ideal mountlngs for the actuating elements and effect rigidity of the piston actuating structure.

A further object is the provision in a hydraulic 2 pump of means to positively locate the cylinder barrel or rotor against axial displacement, and

. prevent undue axial thrust on the barrel whichv L might result from the use of an improperly designed coupling between the pump and its driving motor e. g. such as would by reason of axial thrust tend to close the necessary clearance between cylinder and valve and thus create too tight a t therebetween and cause heat and wear and excessive dead load friction.

3 A further object is the novel application of coupling means between a cylinder block impeller and radial piston actuating relatively eccentric members of a pump of the class shown. to minimize load on the pistons and piston crossheads when the machine is set at maximum piston stroke and power output, thereby to increase the eflciency and useful life of the mechanism.

Other more speciiic objects and advantages will appear from the accompanying drawings and specications.

In the drawings:

Fig. 1 is a horizontal sectional plan view of'a pump embodying the novel characteristics hereof;

4 Fig. 2 is a transverse sectional view of the pump taken substantially along the line 2--2`on Fig. 1;

Fig. 3 is an end view of the novel cylinder block for the rotor looking toward the arrows of line :v -a: Fig. 4; and

Fig. 4 is a longitudinal sectional view, partly inelevation of the novel cylinder block rotor. taken on line 4-4 on Fig. 3.

Referring to the drawings in detail, the pump disclosed for illustration is enclosed within a liquid tight reservoir, comprising a main body member I having a generally cylindrical portion I and bell shaped central portion having a hub 2, the casing being completed by a bell shaped cover member 3 arranged to close the body member I of the casing in concentric relation thereto.

The rotor is mounted in the casing and comprises, as shown, a cylinder block forging 4 having a forged shaft portion 5 adapted for driving connection with a suitable source of motive power, such as an electric motor, Diesel engine etc. (not shown).

It being one of the principal objects of this invention to provide an eflicient pump wherein the relatively rotating hydraulic parts are in precise alignment as to reduce wear, vslip friction and undue depreciation of the device, the hub portion 2 is made very heavy and is accurately machined to rigidly support a cylindrical valve or pintle I0, which is tightly'pressed into the bore of the hub as at II. Further, in` line with said object, I form the valve supporting hub 2 integral with the body portion I vso that the I9 supported thereby, also to be later described.

It will be seen that by the absolute concencover 3, through its concentric seat 8, the'surfaces supporting the bearing I9 in the cover 3 will also be in a high degree of precision concentricity with the bearing I9, and thereby the entire rotor 4 and impeller shaft 5' will bew mounted concentrically with the pintle I0, resulting invas nearly as possible, a frictionless mounting for the rotor 4 as well as true alignment and necessary uniform fitting on all sides with the pintle I0.

In pumps of prior design, where the pintle I5 rigidly mounted in a separate valve end head, such accurate alignment could not be obtained, resulting in a less eflicient and sturdy pump, due to misalignment of the rotational axis of the cylinder block and pintle axis and to crowding of bearings, and excessive wear and vibration took place; also excessive slip and low hydraulic efficiency. Myy novel structure eliminates such faults resulting from misalignment, by the simultaneous provision of pintle bore and end cover centering surface as at 8 in a one piece body casing.

'I'he cylinder block forging 4 is provided with appropriate reduced portions (see Fig. 4) and thrust shoulders as at 4a, in order to positively take up thrust in two directions imposed respectively by the slight tapered fit of the pintle in `the rotor and by the driving coupling attached to the shaft such as 5.

The' bearing I9 has its inner race member II in contact with one of the thrust shoulders 4a to locate the rotor, and said race member is secured to the cylinder block or rotor 4 by a lock nut 43 threaded onto the rotor body so that the bearing I9 is locked positively to the rotor thus opposing any axial thrust on the rotor such as would widen or close the accurate hydraulic tting relationship-close running clearancebetween the pintle and rotor. The concentricity or axial alignment of the bores 6 and 'I of the body'members I and 3 further provides concentricity for the bores 6 and I respectively so that bearings I8 and I9 and the bore for the pintle may be made at the sametricity of the pintle I0 the bearing I8 and end Lrotor supported thereby will rotate accurately about the axis of the casing parts I and 3 and the axis of the 'pintle carried rigidly by and coaxially of the casing part I, which conditions are of great importance from the standpoint of mechanical and volumetric eiiiciency of the pump.

'Ihe pintle Il) is providedwith a suction port I2 and a pressure port I3 in a Well known manner, which ports are reversible in action by a single straight line shift of the relatively eccentric mechanism, to be hereinafter described, which operates the pistons. The enlarged portion of the pintle I0 is further provided with' inlet and outletJ passages as at I4 and I5 respectively, which passages are connected respectively with the pump ports I2 and I3, pump mains being provided in the valve supporting hub 2 of the casing in the usual manner (not shown).

As hereinabove mentioned the supporting bore Il for the pintle on the hub 2 is machined in the same tool-setting as that of counterbore 6 and centering Vsurface 8 of the body casing to thereby make the axis of the pintle and the axis of the body casing I and 2 coincide. After this has been accomplished, the rest of the -assembly will automatically assume proper alignment in the pump mechanism. r

The cylinder block 4 in addition to pintle receiving concentric bores I0' and II is provided with a central spider flange as at 44 in the zone of the radial cylinder bores 22, which cylinders communicate with the barrel bore I0' through appropriate radial ports 22.

Each individual cylinder 22 is fitted with a properly shaped piston 23 for radial reciprog cation in the respective cylinder, for withdrawing operatinguid from oneof the pintle ports I2 or I3 and discharging it into the other of said ports.

Each piston is provided with a flattened head 'portion 26 adapted to be guided radially in complementary radial ways 45 in the flange 44 of the forging 4 (see Figs. 3 and 4), the increased dimensions of the heads 26 in the zone of the flange being sufficient to take the transverse load component of the radial pistons -Which load component results from the relative eccentricity between the axis of the barrel 4 and the axis of the crosshead actuating elements 36` and 36 etc. these elements comprising, in part, ball bearing assemblies to be presently described. Such transverse load components are proportional to the eccentricity of the actuating assembly and stroke of the pistons and are greatest at full stroke and diminish as the eccentricity of the actuating elements and the stroke of the pump pistons approach zero, at whichvpoint there are no transverse strains on the pistons resulting from the hydraulic piston load. The complementary contacting surfaces of the piston heads 26 and ways 45 are preferably cylindrically generated as by a boring operation when the radial cylinders 22 are A bored. These surfaces may however be non-circular (flat e. g.) if it is desired that the pistons be prevented from turning even slightly in the cylinders. f

The general arrangement of adjustable piston actuating elements is as follows: An actuator supporting ring 4I is mounted to slide on suitable surfaces 4Ia and 4Ib, Fig. 2, machined in the cylindrical shell portion I' of the casing pa'rt I, actuation of the ring for adjustment of pis ton stroke and for reversal of the direction lof flow of uid through the pump being effected in more or less conventional fashion by suitable bars 40 and 40' extending into the casing from oppoamifrao site directions through suitable bores and secured .as by threaded connections 39 and 39 to the ring 4|. The inner surfaces of the ring are accurately machined to receive, as by slip llt, the outer race members 3.1 and 31' of the ball bearing assemblies heretofore mentioned, these being4 malntained in position against a central rib 42 forming shoulders for both members 31 and 31', by appropriate snap rings 38 and 38. The balls 36 and 36 roll in the usual raceways of the outer and inner race members, the latter being indicated at 34 and 34' respectively.

The pistons are actuated inwardly by the inner 6 surfaces of the inner race members 34'and 34' which contact directly with cross pins 25 carried in the heads 26 of the pistons as will now be described.

In order to further prevent wear and excessive friction between the heads 26 and the radial guide surfaces 45 I provide anti-friction quill or needle bearings 24 and small crosspins 25 which due to the novel disposition of the crosshead actuating elements 36, 36 etc. thereto are subject to shearing stresses only, and are not only reduced in dimensions but also in mass, sothat my novel pump and its pistons have substantially a minimum amount of reciprocating masses, compared to prior pumps of similar character, wherein there are large reciprocating masses. The reciprocating mass forces of the pistons and parts secured thereto are similar in effect to the mass forces imposed by piston rods, crossheads etc. of

reciprocating engines and in radial piston typepumps become enormous at pump speeds such as 1000 to 2000 Il..l P. M. The improved crosshead assemblies herein shown and relative disposition thereof to anti-frictionally supported reactance means, and particularly the reduced length and masses of the piston assemblies marks a radical departure from and improvement over pumps having relatively heavy shoes or sliding blocks or T-heads required to reciprocate at such high speeds as above mentioned. I

Further noteworthy novelty of my invention resides in the provision of piston actuating rings 21 and 28, which serve two purposes: first they actuate the pistons during outward stroke by their lip portions 21' and 28' respectivelybearing directly on the cross pins--for positive displacea locate the bearing members 36 and 36 positively against axial separation. In orderto set the axial distance of said bearings by the rings 21 i and 28, I provide a circular series of hollow spacers 32 (Figs. l and 2) which determine that the axial distance between the bearings will be equal to the width of the rib 42 of the control ring 4I against which the outer race members are maintained as described above. The rings 21 and 28 are clamped together in rigid relation to each other against the spacers 32 by suitable screws 3|, corresponding in number to the spacers and` passing through registering openings in the rings 21' and 28, being threaded into one of the rings as at3|' and having heads 3|" abutting the other of said rings. The screws may be locked in position in any suitable manner. The spacers are of sufcient length to provide, between the rings 21 and 28 definite clearance spaces for the piston heads between the inwardly disposed surfaces of the race members 34 and 34' and the rings 21 and 28. The clearance is somewhat exaggerated on the drawings'for clearness of i1- lustration. When the ring securing and clamping screws 3| are set and locked, the small flanges 33 and 33' exert suillcient force inwardly on the inner bearing race members tov take up all unnecessary play and these small flanges thus cooperatewith the shoulders on the rib 42 and with the snap rings 38 and 38' to hold the bearing race members positively in freely operating alignment but against axial displacement in either direction. Nevertheless the parts of the relatively eccentric mechanism are capable of being easily and quickly assembled and later disassembled-as for inspection, replacement or repair of partsin an obvious manner.

In addition to the clamping and mounting purposes of the screw and sleeve arrangement 3|, 32 above described these parts in connection with the rotor forgingserve as positive driving coupling elements between the relatively eccentric piston` actuating mechanism and the rotor during certain conditions as will now be described.

In my novel cylinder block forging the flange portion 44 is provided a plurality of circumferentially deployed axial openings or holes 30, one between each two radial guide ways 45 in order to provide free passage for the screws 3| and spacers 32 from the ring 21 to the ring 28. Since Pif) however the path of every point of the cylinder block 4 relative to the piston actuating assembly is a circle struck around the point in question with a radius corresponding to the extent of eccentricity of the actuating assembly at any setting thereof, it is evident, that a circle, struck about the axis of the members 3| ample to provide circular clearance for .the members 3| in the maximum eccentric position of the actuating assembly, must be on a radius at least equal in length to thev maximum eccentricity of the pump.

By providing exactly this clearance then at maximum eccentricity and stroke the relatively eccentric mechanism comprising the bearings 36, 36' etc. and rings 21, 28, will be positively driven by the impeller barrel 4 and consequently at this maximum power transmission of the pump, the cross pins 25 will be unloaded from excessive friction and wear incident to transmitting the driving torque from the piston cross pins to the annular surfaces of the rings 2.1 and 28 or the inner bearing race members as the case might be.

At shorter strokes than maximum my novel structure will, upon initial operation, provide positive starting of the entire rotary assembly of the pump, and thus prevent the cross pins 25 y from racing with excessive speed intheir annular tracks.

So far as I know such positive driving coupling connection between the relatively eccentric parts at maximum stroke of the pistons, relieving the pistons from having to transmit the driving torque, is entirely new in a mechanism of this class, likewise I believe the compact arrangement of parts is entirely new.

I claim:

1. In a pump or motor of the character described. a casing, a rotor andsupporting bearings therefor in the casing, a valve pintle in the casing disposed coaxially with said rotor and casing, relatively eccentric mechanism slidably mounted in said casing and includinga ring and sliding support therefor in the casing, antifriction bearings in said ring axially separated to provide a clearance space between said bearings, the rotor having radial guide ways and piston heads in said ways between said bearings in said clearance space, each head carrying a cross pin extending axially of the rotor, a piston associated with each piston head, a cylinder for` eccentric mechanism.

2. In a pump or motor of the character described, a casing, a piston carrying rotor `iournaled axially in the casing, relatively eccentric mechanism surrounding the rotor and disposed within the casing for operating pistons carriedv by the rotor, said Ymechanism comprising an outerring member mounted in thecasing', antifriction bearing assemblies including inner and outer race members in spaced'relation to each other, said assemblies being mounted within the outer ring, inner ring members each having ilanges lying axially outwardly from said bearing. assemblies to retain the inner races against axial separation, said inner ring members cooperating with the inner race members of said bearing elements to provide circular track ways, means rig idly securing said inner ring members together with the flanges in clamping relation to the inner race membersof the bearings, and means carried by the pistons extending laterally there-I from into operative engagement with said circular tracks for actuation thereby o n rotation of the rotor. I

3. In a pump or motor of the class described, a casing, a rotor therein, piston and cylinder assemblies carried by the rotor, bearing means supporting the rotor, valve means rigidly mounted in the casing and cooperatively associated with the piston and' cylinder assemblies of the rotor, relatively eccentric mechanism'mounted inthe casing, said mechanism comprising an outer ring,

and provide a track surface for effecting positive outward movement of the pistons, and means rigidly coupling said mounting rings, said outer ring having inwardly extending means axially abutting said beari'ngs and spacing the same, the coupling means and mounting rings cooperating to hold the bearings in abutment with said abutting and Spacing means.

4. Inl a pump or motor of the character described, a casing, a rotor rotatably mounted in the casing and having a plurality of radial 4cylinders, valve means for the cylinders, relatively eccentric reactance means mounted in said casing :and including a support in the casing, anti-friction bearingassemblies in said support and axially spaced to provide a clearance space between said bearing assemblies, pistons in the cylinders having piston heads accommodated between said bearing assemblies in said clearance space, each head carrying thrust means extending axially of the rotor beyond the associated head, mounting rings for the bearing assemblies xedly lmounted inside thereoi and recessed to provide with the assemblies grooves between the bearing assemblies and the associated mounting ringsl to receive the piston thrust means in direct load transmitting engagement with the assemblies, and means constraining each bearing assembly and associated mounting ring from axial displacement relative to the other bearing assembly and associated mounting ring.

5. In a pump or motor of the character described, a valve pintle, a cylinder barrel mounted for rotation about said pintle and being formed with a plurality of circumferentially spaced radially disposed cylinders, pistons reciprocable respectively in said cylinders, a reactance device mounted eccentrically with respect to 'said cylinder barrel, said reactance device including rotatable axially spaced members each formed with a continuous circular trackway and each having a. radial portion, said cylinder barrel having a radial portion disposed between said spaced members, and said pistons respectively having outer portions disposed between said spaced members, thrust-transmitting means connected to each piston outer portion and operatively engaging' the circular trackways of said reactance device spaced members on opposite sides of the piston outer portions, and circumferentially deployed cylindrical coupling and spacing means extending parallel to the axis of said barrel and connecting said reactance device members together inl fixed spaced relation, said cylinder barrel radial portion being formed With-circumferentially deployed cylindrical openings` extending parallel to the barrel axis and through which said coupling and spacing means extend respectively, the difference between the diameters of said open- .ings and the diameters of said coupling and spacing means being at least equal to the eccentricity of said reactance device relative to said cylinder scribed, a plurality of rotatable radially disposed piston and cylinder assemblies each comprising a relatively reciprocable part and a relatively nonreeiprocable' part; a reactance device eccentrically disposed with respect to said assemblies and comprising axially spaced anti-friction bearing assemblies each including an outer race and an inner race and a plurality of interposed antifriction elements, two reactance rings, one associated with each of said bearing assemblies, each ring having a portion underlying and engaging a part only of the associated inner race' and another portion underlying but being spaced inwardly Afrom the remaining part of said inner race to provide a resultant arcuate track groove, the track groove thus formed by each inner race and associated ring facing and opening towards the similar groove formed by the other inner race -and ring; and thrust-transmitting means extending through said ,relatively reciprocable elements and into said track grooves and operatively and directly engaging said inner' races.

'7. In -a pump or motor of the character described, a plurality of rotatable radially disposed piston and cylinder assemblies each comprising a relatively reciprocable part and a relatively nonreciprocable part; a reactance device eccentrically disposed with respectjto said assemblies and comprising axially spaced anti-friction bearing assemblies each including an outer race and an inner race and a plurality of interposed antifriction elements, two reactance rings. one associated with each of said bearing assemblies, each ring having a portion underlying and engaging a part only of the associated inner race and another portion underlying but being spaced inwardly from the remaining part of said inner race to provide a resultant arcuate track groove, the track groove thus formed lby each inner race and associated ring facing and opening towards the similar groove formed by the other inner race and ring, said relatively reciprocable members having portions projecting between said rings and between adjacent side surfaces of said inner races, said rings having flanges respectively engaging the remote side surfaces of said innerraces to maintain said inner races against axial movement away from each other; and thrusttransmitting means extending through said relatively reciprocable elements and into said track grooves and operatively and directly engaging said innerv races.

' ELEK K. BENEDEK. 

